Anon Still living,
It takes time for medication for depression to make a difference.
Is it companionship that you think you will lose so you "can't fend for" yourself? Companionship comes in many forms and anyone at any age can learn to have new companions. I'd rather be with my dog for companionship than with someone who makes me feel bad.
Hang in there. Things change for everyone in life, and that's not always a bad thing.